Tie rod with small increment variable effective length



G. F.- BOWDEN 3,362,678 TIE ROD WITH SMALL INCREMENT VARIABLE EFFECTIVELENGTH Jan. 9, 1968 2 Sheets-Sheet l Original Filed Sept. 17, 1964//vv/vro GEORGE E 50 was/v G. F. BOWDEN Jan. 9, 1968 TIE ROD WITH SMALLINCREMENT VARIABLE EFFECTIVE LENGTH 2 Sheets-Sheet 2 Original FiledSept. 17, 1964 M h y Um a Q E m //V VE N TOR GEORGE F. BOWDEN UnitedStates Patent ABSTRACT OF THE DISCLOSURE A flat tie rod adapted for usewith the opposed sides of a concrete wall form and characterized by thefact that it is slotted in such a manner as to accommodate smallincrements of effective form width by proper selection of slots forattachment of the tie rod to the opposite form sides.

This application for United States Letters Patent is a continuation ofapplication Ser. No. 397,198, filed by me on Sept. 1-7, 1964, nowabandoned, and entitled, Tie Rod With Small Increment Variable EffectiveLength.

The present invention relates generally to tie rods for use inconnection with concrete wall forms and the like and has particularreference to that type of tie rod which is designed for use inmaintaining the opposed spaced apart sides of a standard or conventionalconcrete wall form in properly spaced relationship and in holdingcertain of the upstanding edge-to-edge panel units that form the formsides against outward displacement during pouring of wet concrete intothe form interior. Still more specifically, the invention is concernedwith a frangible tie rod like that which is shown and described inUnited States Patent No. 2,948,045, granted on Sept. 9, 1960, andentitled, Tie Rod Assembly for Concrete Wall Forms and Cone The-refor,such a tie rod being in the form of an elongated strip of flat, narrowmetal stock and being designed and adapted to project completely throughthe associated concrete wall form and the poured concrete within theform so that, after hardening of the concrete and removal of the panelunits, the projecting ends of the tie rod may be bent, twisted orotherwise worked in various directions in order to weaken the metal ofthe rod at the regions where the rod ends enter the concrete as apreliminary to ultimate rupture or severance of the projecting ends ofthe rod from the concrete embedded intermediate portion of the rod.

Tie rods of the type and character under consideration are specificallydesigned for use in connection with a prefabricated concrete wall formwherein the individual panel units are assembled at the factory ratherthan in the field and consist of rectangular plywood facings andrectangular reinforcing frames around the facings and wherein thevertical and horizontal marginal frame members which are in the form oflengths of metallic channel stock and are shaped, slotted, notched andotherwise fashioned in order properly to receive the edges of theplywood facings, the projecting ends of the tie rods, and the variousfastening devices or other concrete form hardware whereby the adjacentpanel units may be fastened together in clamped relation. Specifically,the marginal outwardly extending ribs of the vertical frame members ofthe rectangular reinforcing frames of the panel units are notched atspaced points therealong so that, when adjacent vertical frame membersare brought together, pairs of registering notches provide, in effect,openings 3,362,678 Patented Jan. 9, 1968 which receive therethrough theend regions of the flat tie rods which are employed for maintaining theopposed spaced apart sides of the associated concrete form in theirproper spaced relationship. Additionally, the intermediate web portionsof the vertical frame members are slotted in the vicinity of the notchesin the marginal outwardly extending ribs so that the shanks of T-bo'ltsmay be passed through the slots, as well as through slots in the endregions of the flat tie rods as a preliminary to driving wedges throughslots in the shanks of the T-bolts in order to draw the adjacentvertical frame members together and lock the panel units and the tierods in position. Such tie rods, T-bolts and wedges constitutewell-known concrete hardware articles which are commonly employed forreleasably maintaining the individual panel units of a prefabricatedconcrete wall form in proper position.

Tie rods of the type that are disclosed in the aforementioned Patent No.2,948,045 are possessed of limited variable effective length, usually inincrements of three inches. Tie rod adjustment to adapt a given tie rodto the erection of two opposed wall form sides that will make itpossible to construct concrete walls of different thicknesses isattained by providing plural slots in the opposite end regions of thetie rod and then selectively using the slots for T-bolt receivingpurposes. Close spacing of the adjacent slots in the tie rod end regionsin an effort to attain small incremental adjustment of the tie rod isprecluded because such close spacing does not leave sufficient metal inbetween adjacent slots to lend the necessary strength to the tie rodwhen the latter is placed in tension in connection with a concretepouring operation. The use of conventional break backs which are in theform of metal-weakening notches in the side edges of a flat tie rodfurther limits the minimum spacing distance between adjacent slots inthe end regions of the tie rod. Because of the fact that flat tie rodswith plural T-bolt receiving slots in their end regions have hereto-forebeen capable of accommodating wall forms for concrete walls which varyin small increments of thickness, for example, oneinch increments, ithas been necessary for contractors to maintain a large and costlystockpile of flat tie rods of varying lengths, including tie rods oflittle-used lengths.

The present invention is designed to overcome the above-noted limitationthat is attendant upon the construction and use of conventional fiat tierods with slotted end regions and, towards this end, the inventioncontemplates the provision of a tie rod which will accommodate theconstruction of concrete walls, the thicknesses .of which may vary insmall increments, for example, in-

crements of one inch, throughout a wide range of efiective tie rodlengths.

The provision of such a tie rod constitutes the principal object of theinvention and it is a further object to provide a tie rod having slotstherein for effective length adjustment as well as break backs, yet inwhich the distance between adjacent slots is well beyond the safe limitfor intervening metal so that the tie rod as a whole is possessed of thenecessary strength when it is placed in tension in connection with usethereof.

A further object of the invention is to provide a fiat tie rod whichemploys for its attachment to adjacent abuttin vertical frame members ofthe reinforcing frames of the associated edge-to-edge upstanding wallform panel units conventional unmodified T-bolt and wedge assemblies,and which, moreover, requires no additional fastening means ormodification of the vertical frame members to which it is attached.

A still further object of the invention is to provide a flat tie rod ofthe aforementioned type and character and in which visual means areprovided for facilitating selection of the particular slots which are tobe employed for T-bolt reception in the erection of a form for aconcrete wall of a given thickness, thus eliminating the necessity ofmeasuring the distance between slots in the end regions of the tie rod.

Other objects and advantages of the invention, not at this timeenumerated, will readily suggest themselves as the following descriptionensues.

In the accompanying twosheets of drawings forming a part of thisspecification, one illustrative embodiment of a tie rod constructedaccording to the present invention, is shown, such drawings illustratingin detail the manner of installation of the improved tie rod in aconcrete wall form.

In these drawings:

FIG. 1 is a fragmentary perspective view, partly in section, of aconcrete wall form installation showing two of the improved tie rodsoperatively installed therein;

FIG. 2 is a fragmentary perspective view, partly in section, showing aportion of the concrete wall structure that is produced by the form ofFIG. 1, with one of the improved tie rods in position within thehardened concrete of the wall structure preparatory to fracture andremoval of the end regions of the tie rod;

FIG. 3 is an end elevational view of a limited portion of the structureof FIG. 1; and

FIG. 4 is an enlarged side elevational view of a tie rod embodying theinvention.

Referring now to the drawings in detail and in particular to FIGS. 1 and3, a fragmentary portion of a composite concrete wall form ofconventional construction is illustrated, such structure beingdesignated in its entirety by the reference numeral 10. The concretewall form is made up of two opposed spaced apart sides 12 and 14- in theform of two opposed rectilinear series of rectangular panel units 16with the units of each series being arranged in upstanding andedge-to-edge relationship. The panel units 16 of the two series aremaintained in spaced parallel relationship by means of tie rods 18 whichare constructed according to the present invention, two such tie rodsbeing illustrated in FIG. 1 in connection with two adjacent panel unitsof each of the two concrete wall form sides 12 and 14 in the productionor fabrication of a concrete wall 15.

The individual panel units 16 are of the prefabricated type known asSteel-Ply panels. Such panels are manufactured and sold by Symons Mfg.Company of Des Plaines, Ill., and consist of a rectangular plywoodfacing 21} havingmarginal rectangular reinforcing frames of steel orother suitable metal applied to the outer faces thereof. Such framesconsist of :vertical and horizontal frame members, only the verticalframe members 22 being illustrated in the drawings. At appropriatelevels in the concrete wall form 10, suitable horizontal crossbars 24 ofangle shape design extend across the front faces of the plywood facingsand have their ends fixedly connected to the vertical members 22 of thereinforcing frames.

Each vertical frame member 22 is in the form of a structural steel orother metal bar which is generally of shallow U-shape cross section andcomprises spaced marginal outwardly extending parallel ribs 26 and 28and a connecting or intermediate web portion 30. On their inner faces,the web portions 30 of the vertical frame members 22 are inwardly andlongitudinally extending ribs 32 which define shallow angular grooves orrecesses 33 for reception therein of the vertical edge regions of theplywood facings 20. The ends of the horizontal crossbars 24 are weldedto the inner faces of the web portions of the vertical frame members 22.At vertically spaced regions along the vertical frame members 22, theribs 26 and 28 are provided with notches 34 to accommodate the slottedend regions of the tie rods 18, while the web portions 36 of thevertical frame members 22 are formed with horizontally extendingrectangular slots 36. The latter are in horizontal register with thenotches 34 and are adapted to receive therethrough the shanks ofconventional T-bolts 38. Such shanks have longitudinally extending slots39 in their free ends and such slots are adapted to receive verticalwedges 40 which cooperate with the T-bolts 38 in holding the adjacentabutting vertical frame members 22 in clamped relation, all in a mannerthat will be made clear presently when the nature of the tie rods 18 isbetter understood. Since both illustrated tie rods are the same, but onewill be described and it will be identified by the reference numeral 18.

As best shown in FIG. 4, the tie rod 18 is in the form of a length offlat steel or other metal stock of rectangular cross section, and it isof a longitudinal extent greater than the overall width of the form 10.The medial region of the tie rod is imperforate but the opposite endregions thereof are slotted in a novel manner and in accordance withcertain considerations pertaining to the desired width of the concretewall which is to be produced in connection with normal utilization ofthe two form sides 12 and 14.

The right-hand end region of the tie rod 18, as viewed in FIG. 4, isprovided with a series of four elongated longitudinally extending slots50, while the left-hand end region is provided with a series of threesimilarly elongated longitudinally extending slots 52. The spacingbetween adjacent slots 50 is different from the spacing between adjacentslots 52, the relative spacings being critical and based upon thedesired variable widths which the concrete wall 15 is capable ofassuming while utilizing the same tie rod.

According to the present invention, it is desired that the tie rod 18 beemployed in constructing concrete walls which vary in width byincrements of one inch, ranging from a minimum wall thickness or widthof four inches to a maximum thickness of sixteen inches. The over-alllength of the tie rod 18, the axial extent of the slots 50 and 52, andthe positioning of these slots, have been selected specifically toaccommodate maximum and minimum wall thicknesses and intermediateincremental thicknesses as stated above.

Accordingly, the axial extent or length of each slot 50 and 52 isseven-eighths of an inch. The slots 50 are spaced apart on two-inchcenters, while the slots 52 are spaced apart on three-inch centers. Eachof the slots 52 has associated therewith a pair of opposed break backnotches 54, such notches being formed in the side edges of the tie rodand being spaced inwardly from their respective slots toward the centralregion of the tie rod a predetermined distance. These pairs of breakback notches 54 weaken the tie rod at various break-off points which areadapted to lie within the confines of the completed concrete wall 15 andfacilitate the breaking-off of the left-hand projecting tie rod end in amanner well known in the art. The slots 50, with the exception of theinnermost slot 50, have no break back notches associated with them.Whereas, the break-off points afforded by the notches 54 liesubstantially centrally of the intervening regions of the tie rodbetween adjacent slots 52, similar break-01f points, if provided for theslots 50, would entail the creation of notches in close proximity toadjacent slots 50 and would thus impair the tensional characteristics ofthe tie rod beyond the danger point.

The tie rod 18 is useable in the manner of a conventional flat-slottedtie rod by selecting one of the slots 50 and one of the slots 52 forreception therethrough of the shanks of two of the T-bolts 38. The panelunits 16 of the wall form sides 12 and 14 are erected in theiredge-to-edge relationship and the tie rods 18 are positioned in thevarious horizontally aligned notches 34 as shown in FIG. 1. The shanksof the T-bolts 38 are then passed through the slots 36 in the webportions 30 of the vertical frame members 22 and the selected slots 50and 52 in the end regions of the tie rods 18, and thereafter,

the wedges 40 are projected through the slots 39 in the free ends of theshanks of the T-bolts and driven to a home position to clamp adjacentpanel units of the wall form sides 12 and 14 in position in the usualmanner of erecting such a concrete wall form.

According to the present invention, the width of the completed concretewall 15 is determined by the two particular slots which are selected forT-bolt reception. As best seen in FIGS. 3 and 4, the slots 50 arelabeled 2, 4, 6 and 8, reading from left to right, while the slots 52are labeled 2, 5 and 8, reading from right to left. The labeling may beeffected by stamping the numerals directly on the body of the tie rod 18in the vicinity of the related slots. The slots are so positioned andspaced apart that the sum of the numerals represented by the labelingwhen one slot 52 and one slot 50 are selected for T-bolt reception,represents the width in inches of the particular concrete wall whichwill be formed. For example, if the tie rod 18 is operatively installedin the wall form 10, utilizing the two slots 52 and 50 labeled 8, thenthe resultant concrete wall width will be sixteen inches. For aneleven-inch wall, the slot 52 labeled 5 and the slot 50 labeled 6 willbe selected for T-bolt reception. Similarly for a nine-inch width wall,the slot 52 labeled 5 and the slot 50 labeled 4 will be selected, thisbeing the thickness dimension of the concrete wall 15 shown in FIG. 2.

To attain these ends, tie rod length, slot elongation, adjacent slotspacing, and the extent of the imperforate medial region of the tie rod18 are critical. Reference to FIG. 3 will reveal that in a conventionalSteel-Ply panel unit, the distance between the center of any given slot36 and the plane of the plywood facing 20 is on the order of one andone-half inches. Thus, if the centerto-center distance between the slot52 labeled 5 and the slot 50 labeled 4 is twelve inches, use of thesetwo slots for T-bolt receiving purposes will result in a spacing of nineinches between the respective planes of the two opposed panel facings20. Similarly, the center-to-center distance between any two given slotsin the two series of slots 50 and 52 is three inches greater than thesum of the labeling applied to such slots. Therefore, the longitudinalextent of the imperforate medial region of the tie rod between the twoinnermost slots 50 and 52 labeled 2 is seven inches less the length ofone slot or, specifically, seven inches less seven-eighths of an inchor, namely, six and one-eighth inches.

It is to be noted that the region of break-E that is established by anypair of notches 54 will, regardless of which slot 52 is selected forT-bolt reception, lie just inwards of the confines of the Wall form side12 so that it will become embedded in the wall-forming concrete when theconcrete is poured. This break-off region will lie near the adjacentside surfaces of the wall 15 after the concrete has hardened. The use ofbreak back notches in connection with three of the four slots 50 is notnecessary or desirable inasmuch as when any one of these slots isselected for T-bolt reception, the effective plane of the adjacent panelunit facing 20 will intersect the next adjacent slot inwardly of the tierod. Only the innermost slot 50 labeled 2 need be provided with breakback notches '4 and they are located a slight distance inwards of theinner end of the innermost slot 50. The intersection of the effectiveplane of the associated plywood facing 20 with a given notch 55) weakensthe tie rod at the region of intersection, and thus, in effect,establishes a break back.

The provision of a conventional break back, i.e., one which is createdby the formation of opposed notches 54 in the side edges of the tie rod18, is illustrated at the lefthand side of FIG. 2 wherein one pair ofnotches 54 lies just inside the confines of the concrete wall 15 and isembedded therein so that the left-hand projecting portion or end regionof the tie rod containing the two slots 52 labeled 8 and 5 may be bent,twisted or otherwise worked 6 so as to effect a break-01f in thevicinity of said one pair of notches 54. At the right-hand side of FIG.2, no such notches 54 are apparent but the outer end of the innermostslot 50 labeled 2 is intersected by the plane of adjacent side face ofthe concrete wall 15 so that when the right-hand projecting portion orend region of the tie rod 18 containing the slots 50 labeled 4, 6 and 8is similarly twisted or otherwise worked and this portion or end regionof the tie rod breaks off in the vicinity of the slot 50 labeled 2 wherethe metal of the tie rod is weakened. Whichever of the three slots 50labeled 4, 6 and 8 is employed for T-bolt receiving purposes, the nextadjacent notch in the inward direction of the tie rod will beintersected by the plane of the adjacent side face of the concrete wall15 after the wall has been stripped of the panel units. The innermostslot 50 labeled 2, having no adjacent inside slot, requires associatedbreak back notches 54 which become effective for break-off purposes onlywhen the slot labeled 2 is employed for T-bolt receiving purposes.

The invention is not to be limited to the exact arrangement of partsshown in the accompanying drawings or described in this specification asvarious changes in the details of construction may be resorted towithout departing from the spirit or scope of the invention. Forexample, the dimensions specified herein and certain of which have beenapplied to the drawings by labeling are predicated upon the constructionof concrete walls, the thicknesses of which vary in increments of oneinch and between a minimum wall thickness of four inches and a maximumwall thickness of sixteen inches. Obviously, if wall thicknesses are tobe varied by increments expressed in units other than inches, forexample, in the metric system of measurement, different and appropriateslot spacing will be resorted to. Therefore, only insofar as theinvention has particularly been pointed out in the accompanying claimsis the same to be limited.

Having thus described the invention what I claim as new and desire tosecure by Letters Patent is:

1. A slotted tie rod for holding a pair of opposed upstanding ooncretewall form panel units in spaced relationship, said panels being of thetype including a rectangular plywood facing with marginal metal studdinghaving anchor slots therein designed for register with selected tie rodslots and in which the centers of said anchor slots are spaced from theeffective plane of the plywood facing by a distance on the order of oneand one-half inches, said tie rod comprising a narrow one-piece strip offlat metal stock presenting straight parallel longitudinally extendingside edges, one end region of said strip being provided with a firstlongitudinally extending row of longitudinal slots which are no lessthan three in number are spaced apart on three-inch centers, all of theslots being of equal longitudinal extent and onthe order ofseven-eighths of an inch in length, said side edges at regions spacedinwardly of each slot being provided with a pair of opposed notches theexistence of which weakens the metal of the tie rod and establishes abreak back, each break back being spaced from the center of itsrespective slot by a distance on the order of one and threefourths of aninch, the other end region of said strip being provided with a secondlongitudinally extending row of longitudinal slots which are no lessthan four in number, are spaced apart on two-inch centers, and likewiseare of equal extent and on the order of seventheighths of an inch inlength, said side edges at a region spaced inwardly of the innermostslot in the second row of slots being provided with a pair of opposednotches which likewise establish a break back, said latter break backbeing spaced from the center of said innermost slot by a'distance on theorder of one and three-fourths of an inch.

2. A slotted tie rod as set forth in claim 1 and wherein thecenter-to-center distance between the innermost slots of the two rows ofslots is on the order of seven inches,

7 and wherein the slots of thefirst row are progressively labelled withnumerical designations having an arithmetical progression of three whilethe slots of the second row are similarly labelled with numericaldesignations having an arithmetical progression of two, the innermostslot of each row being labelled with the numerical desiglabelled withnumeric-a1 designations having an anith-meti- References Cited UNITEDSTATES PATENTS 3/1958 Kenney 249-214 8/1960 Imonetti 249-214

